Phonograph



Nov. 16, 1937. c. HUENLICH PHONOGRAPH Filed Sept. is, 1954 INVENTOR Char/es l'luenffc/z A TTORNEY Patented Nov. 16, 1937 UNITED stares e TENT orrics Thomas A. Edison,

Incorporated, West Orange,

N. J., a corporation of New Jersey Application September 15, 1934, Serial No. 744,111

Claims.

This invention relates to phonographs and more particularly to phonographic sound boxes which are adapted to either record or reproduce. Such sound boxes are in common use on business 5 phonographs which are adapted to record dicta-- tion and which are also arranged to permit re production of dictated matter by a simple manipulation of a sound box controlmember.

In such machines, it has been common prac- 0 tice to. provide a recording stylus and a reproducing stylus either of whiohmay cooperate with a single diaphragm and the record tablet to per- -form the function indicated the sound box control member.

1511 box is shown and desoribed in U. S. Patent No.

1,420,316, issued June 2%, 1922, to N. H. Holland.

This structure or modifications of it have cnjoyed a considerable commercial success over a number of years in connection with business phonographs.

In a combined recording and reproducing sound box of the construction disclosed in the Holland patent mentioned above, the diaphragm is mounted in a light casing which is pivotally connected to a frame carried by the movable carriage of the phonograph. Ihe diaphragm carriesa recording stylus which is mounted upon a stirrup projecting some distance below 3o sired torecord, the recording stylus is biased into engagement with the record tablet by the weight of the diaphragm and its associated casing; 'The weight of the casing is made suchthat the pressure exerted upon the record is just sufficient to cause the stylus to cut a groove of the desired depth during the recording operation. However, when it is desired to reproduce the recorded matter, it is necessary to cause the reproducing stylus to engage the record tablet with a pressure considerably greater than that used in recording and to provide considerable ad-' ditional inertia in the sound box. Inthe structure'shown in the above-mentioned Holland patent, this is accomplished by providing a floating the recording stylus may pass. This floating weight serves no purposeduring the process of 50 recording and it is essential that some provision be made for then preventing this weight from interfering with the action of the diaphragm and its associated casing or from damaging thereo- 0rd tablet. This is accomplished by providing 55, the floating weight with an advance ball, usually by the position'or". Such a sound the diaphragm. This assembly is arranged so that when it is de-.

tablet by the stylus Weight which is normally positioned between the diaphragm and the record tablet and which has a central hole through which the stirrup carrying made of sapphire, which has a polished spherical end portion for engagement with the record tablet, this end portion having a radius considerably greater than that of the reproducing stylus ball. This advanceball is positioned on the floating weight in advance of the recording stylus with respect to the normal direction of traverse of the sound box over the record tablet. Thus while the recorder is advancing across the record tablet, the floating weight'is supported by sliding con- :tact of the advance ball upon the uncut portion of the record tablet in. advance of the recording stylus. 7

While the above described structure has been in common use fora number of years, it has been found that certain disadvantages arise in its use. First, with an advance ball of a comparatively large radius as hereinbefore described, there is a considerable tendency for chips produced by the recording stylus in the process of cutting a groove, to become lodged upon :the uncut portion of the record tablet in advance of the recording stylus and subsequently to be ironed into the smooth surface of the tablet by the advance ball. This results in a roughened and uneven surface on the record tablet which causes the recording stylus to cut a correspondingly rough and uneven groove, thereby materially increasing the surface noise in the record. A second disadvantage of the construction described above is theffact that, with the advance ball in the position described, it is impracticable to record to the end of the record tablet since if this were attempted, the advance ball'would passoif the end of the record tablet and permit the floating weight to' drop onto the record tablet and thereby damage it; the floating Weight in thus dropping would also. force the recorder stylus deeply into the record tablet and the latter would thereby be further damaged.

In order to overcome these disadvantages I propose to utilize, in place of the usual advance ball, a ball having a spherical end portion of substantially the same radius as the reproducing stylus ball; to mount this stylus in an extremely lightweight member which is resiliently secured to the floating weight; and to position this stylus so that it normally rides in that groove which has just been cut by the recording .stylus or in one of the several grooves immediately following the recording stylus with respect to the normal direction of movement of the carriage during recording. In this constructionthe weight supporting ball and its associated mounting are made sulficiently light and resilient so that no appreciable i damage to the'recorded groove is caused, This 55 arrangement has been found to overcome the disadvantages of the previously described structure.

It is therefore the principal object of'my invention to provide means for supporting the floating reproducer weight during recording in a manner which does not cause damage to the smooth surface of the record tablet prior to its engraving by the recording stylus.

It is a further object of my invention to provide a supporting means for the floating reproducer weight which does not prevent recording u to the end of the record tablet.

It is another object of my invention to provide a supporting ball for the floating reproducer weight which normally rides in a groove cut by the recording stylus, but which is so arranged that it causes no appreciable damage to the rec ord groove.

Further objects and features of my invention will be disclosed in the following specification and appended claims.

For a clearer understanding of my invention reference is made to the drawing which accompanies and forms part of this specification and in which:

Figure 1 is a side elevation, partly in section, of the carriage and associated parts of a phonograph embodying my invention, the combined recording and reproducing sound box as shown therein being positioned for recording;

Fig. 2 is a side elevation, partly in section, of a portion of the mechanism shown in Figure 1, but with the combined recording and reproducing sound box positioned for reproducing;

Fig. 3 is a bottom plan View of the combined recording and reproducing mechanism shown in Fig. 1;

Fig. 4 is a part sectional view taken approximately on the line i-4 of Fig. 3;

Fig. 5 is a top plan view of a floating reproducer weight embodying a modification of my invention;

Fig. 6 is a part sectional view taken approximately on the line -45 of Fig. 5;

Fig. 7 is a top plan view of a floating reproducer weight embodying a further modification of my invention; and,

Fig. 8 is a side elevation, partly in full lines and partly in dash and dot lines, of the structure shown in Fig. '7.

Referring to the drawing and more particularly to Figs. 1, 2, 3 and 4, the combined recording and reproducing sound box comprises a frame I having a neck portion 2 adapted to receive one end of a speaking tube (not shown). The sound box is supported in a carriage 3 which is mounted for sliding movement on a pair of guide rods 4, 5.

The frame I has a downwardly extending lug 6 which is slotted at its lower end portion to form a pair of spaced arms i and 8 (see Fig. 3). These arms'are suitably 9 having conical end portions which form pivots and coact with a pair of angular spring arms I I attached to a casing It supporting a diaphragm M. The sound chamber formed within the case ing I0 is connected to the neck 2 by a sliding tube 12. The diaphragm 14 carries a stirrup IE to the lower end of which is secured a recording stylus l6.

It will be seen that when the casing I0 is allowed to swing downwardly, the stylus it will engage a record tablet A mounted in the phonograph, with a pressure determined by the mass of the casing and its associated parts. The redrilled to receive a cross-pin' cording stylus is then in operative position and the reproducer stylus 2|, as will be hereinafter more fully explained, is then in inoperative position. If the record tablet A is then rotated and the carriage 3 is simultaneously moved transversely of the record tablet, the stylus i6 engraves a spiral groove therein. If, during such transverse movement of the carriage 3, the diaphragm is actuated by sound transmitted through the speaking tube and the neck 2, the depth of the groove is varied in accordance with the sound and a record groove of the hill and dale type will thereby be made in the record tablet.

A floating weight which is normally used only in the reproduction of sound, is positioned be tween the sound box and the record tablet. This floating weight comprises a weight l9 which is mounted for limited free transverse movement upon a shoulder screw 23. The shoulder screw 23 is threaded into an L-shaped bracket 22 which is mounted in the slotted portion of the lug 6 and is pivoted on the center portion of the cross pin 9. The weight it is provided with a central hole 25 to permit the stirrup l5 and the stylus it readily to pass therethrough during the recording operation. Also out in the weight is a slot wherein a reproducer stylus arm i3 is pivotally mounted on a pin 26. The outer end of the arm l8 carries the reproducing stylus 2i and the inner end is positioned within the stirrup it at all times. A lever 33 is mounted in the carriage 3 for swinging" movement about the guide rod 4 and constitutes a control member by which the position of the sound box may be selected. The lever 33 controls the operation of a pair of lifting dogs 34 and 35 which co-act respectively with suitably formed lifting tabs on the casing H3 and on the weight it. To effect movement of the sound box to its recording position, shown in Fig. 1, the control lever 33 is moved to its most forward position wherein the dogs 3 and 35 are positioned below their respective lifting tabs so as to permit free downward movement of both the casing i0 and the weight l9. When this occurs the weight 69 moves downwardly to a position in which it is supported from the record tablet, in a manner to be hereinafter described, and in which it plays no part in the process of recording. The casing Iii also moves downwardly until the recording stylus it engages the record tablet in operative position, and accordingly when the tablet is rotated, the stylus i6 engraves a groove therein in the manner described hereinbefore.

When it is desired to reproduce matter which has already been recorded upon the cylinder, the control lever 33 is moved to its most backward position, shown in Fig. 2, in which the lifting dog 35 occupies its lowermost position; but in such movement of lever 33 the lifting dog 34 is moved to its uppermost position and coacts with the tab on the casing It to move the same upwardly until it engages or nearly engages the frame I. The recording stylus is thus placed in inoperative position. Under theseconditions the rear portion of the arm it which lies within the stirrup i5 is moved upwardly by the latter and thereby the reproducing stylus H is brought into engagement with the record tablet. The reproducer stylus is thus placed in operative position. The weight l9 under these circumstances is operative to bias the reproducing stylus into engagement with the record tablet and provides sufficient inertia so that the vibration imparted to the reproducing stylus by the sound grooves of the record tablet is almost wholly transmitted to the diaphragm I 4 through the stirrup l5. The means for supporting the weight l9 during the process of recording comprises a fiat spring 27 secured at its outer end to theweight against the under side of the latter, by a suitable screw 28. At its inner free end the spring 21 carries a stylus or contact ball 30 having a spherical end portion of substantially the same diameter as the rounded end of the reproducing stylus. The spring 21 is positioned in a groove 29 in the weight iii. A screw 3| having a conical end portion 3| is threaded into the weight I 9 and constitutes means for adjusting the position of spring 21 with respect to the weight. The contact ball 30 is positioned somewhat behind the recording stylus l6 with-respectto the normal direction of movement of the carriage. During the operation of recording, the contact ball 30 rides in one of the grooves just previously cut by the recording stylus. The mass of spring 21 and contact ball 30 is made very small so that their mechanical impedance to vibratory motion is very low. Therefore, even though the contact ball 30 is forced into the record grooves under the entire pressure of the weight l9, the damage which is caused thereby has been found to be negligible in all cases. It will be seen that the construction provided permits recording almost to the end of the record tablet since the device which supports the weight I9 is positioned behind instead of in front of the recording'stylus. Furthermore there is little if any tendency to iron thechips produced by the recording stylus into the record table since the diameter of the ball 30 used in my improved construction, is much smaller than that required with the normal advance ball construction.

In Figures 5 and 6 I have shown a modification of my invention as embodied in a sound box of the type shown in Figures 1 to 4. In this modification all parts of the sound box are identical with those of'the sound box structure hereinbefore described, with the exception of the mounting for the weight supporting contact ball. In this case a U-shaped 'memb'er 36 is provided and is pivotally mounted on the pin 20 which serves as a pivotal mounting for the reproducing stylus arm l8. In Figure 5 the weight I9 is shown as viewed from the top and as will be seen the U-shaped member 36 is positioned almost wholly within such weight. Member is biased'to its lowermost position by a torsion spring 31 wound about the pin 23 and carries a contact ball 30 arranged to glide in one of the grooves just previously cut by the recording stylus l6, as described hereinbefore. A tongue 38 provided on member 36 is arranged to coact with a suitable cutout portion 38' of weight I!) to prevent said member from swinging too far in a clockwise or downward direction. In this modification, however, I have shown the contact ball 30' offset from the recorder stylus a much smaller distance to the rear than was the case in the modification first described.

The modified sound box structure shown in Figures 7 and 8 is similar to the corresponding structures shown in Figures 1 to 4 and Figures 5 and 6, as to all features except the weight supporting means. In this modification I provide a bifurcated member 39 which is pivoted on a pin 40 carried by weight I9 and'which is biased to its lowermost position by a coil spring 31' embracing the pin. The pin 40 is supported at its ends in the spaced arms of a bracket 42 which is suitably rigidly secured to weight l9 within a recess provided therefor in the top of the weight.

A contact ball 30" is provided on the member 39 and is disposed substantially in exact alignment with the recording stylus l6 so that it will tend. to glide in the groove just engraved by said stylus. In this construction no additional transverse space whatever is needed for the support ball since the oifset heretofore usually required and employed is eliminated. An extending portion 38 provided on member 39 is arranged to coast with the bracket 42 to prevent excessive motion of said member in an upward direction. Th movement of the member 39 is also adjustably limited in adownward direction by engagement of its extension 38" with a screw 44 threaded into the weight Hi.

It will be obvious to those skilled in the art that my invention may be embodied in many other modifications without departing from the spirit thereof. I

Having thus described my invention, I claim:

1. In a phonographic sound box adapted for coaction with a record tablet, vibratile means, a reproducer stylus and a recording stylus connected with said means and respectively movable at will into and out of operative position with respect to said record tablet, a reproducer stylus biasing weight movable relative to said vibratile means, and means to sup-port'said weight in predetermined position in respect to said record tablet when said recording stylus is in operative position, said last named means comprising a member resiliently connected with said weight and having an end portion adapted for engagement with the record tablet.

2. In a phonographic sound box adapted for coaction with a record tablet, vibratile means, a reproducer stylus and a recording stylus connected with said means and respectively movable at will into and out of operative position with respect to said record tablet, a reproducer stylus biasing weight movable relative to said vibratile means, and means to support said weight in predetermined position in respect to said record tablet when said recording stylus is in operative position, said last named means comprising a member resiliently mounted on said weight and a contact element adapted to glide on the record tablet and carried by said memher.

3. In a phonographic sound box including a recording stylus adapted to traverse and to engrave a groove on a record tablet, and a reproducer stylus, said stylii respectively having operative and inoperative positions with respect to said record tablet, the combination of; a reproducer stylus biasing weight, and means to support said weight in predetermined position with respect to said record tablet when said reproducer stylus is in inoperative position, said means comprising a contact member adapted to glide on the record tablet and mounted on said weight, said member being positioned behind said recording stylus with respect to the normal direction of movement of said stylus across the record tablet. V

4. In a phonographic sound box including a recording stylus adapted to traverse and to engrave a groove on a record tablet, and a reproducer stylus, said stylii respectively having operative and inoperative positions with respect to said record tablet, the combination of; a reproducer stylus biasing weight, and means adapted to support said weight in predetermined position with respect to said record tablet, said means comprising a contact member positioned on said weight to glide in the groove engraved in the record tablet by said recording stylus when said recording stylus is in operative position.

5. In a phonographic sound box including a recording stylus adapted to traverse and to engrave a groove on a record tablet, and a repro- V ducer stylus, said stylii respectively having operative and inoperative positions with respect to said record tablet, the combination of; a reproducer stylus biasing weight, and means to support said weight in predetermined position with respect to said record tablet when said reproducer stylus is in inoperative position, said means comprising a contact member adapted to glide on the record tablet, said member being positioned on said weight in substantial alignment with said recording stylus with respect to the normal direction of movement of the record groove past said member so that said contact member when so gliding will contact an engraved portion of said record tablet. V

6. In a phonographic sound box including a recording stylus adapted to traverse and engrave a groove on a record tablet, and a reproducer stylus, said stylii respectively having operative and inoperative positions with respect to said record tablet, the combination of; a reproducer stylus biasing weight, and means to support said weight in predetermined position with respect to said record tablet when said reproducer stylus is in inoperative position, said means comprising a contact member adapted to glide on the record tablet and resiliently mounted on said weight, said member being positioned behind said recording stylus with respect to the normal direction of movement of said stylus across the record tabiet.

'7. In a phonographic sound box including a recording stylus adapted to traverse and engrave a groove on a record tablet, and a reproducer stylus, said stylii respectively having operative and inoperative positions with respect to said record tablet, the combination of; a reproducer stylus biasing weight, and means to support said Weight in predetermined position with respect to said record tablet when said reproducer stylus is in inoperative position, said means comprising a contact member adapted to glide on the record tablet and resiliently mounted on said weight, said member being positioned in substantial alignment with said recording stylus with respect to the normal direction of 'movement of" the record groove past said member so that the latter when gliding on the record tablet will engage an engraved portion thereof.

8. In a phonographic sound box including a recording stylus adapted to traverse and to engrave a groove on a record tablet, and a reproducer stylus, said stylii respectively having operative and inoperative positions with respect to said record tablet, the combination of; a reproducer stylus biasing weight, and means adapted to support said weight in predetermined position with respect to said record tablet, said means comprising a contact member resiliently mounted on said weight in a position to glide in the groove engraved in the record tablet by said recording stylus when the recording stylus is in operative position.

9. In a phonographic sound box adapted for coaction with a record tablet, vibratile means, a reproducer stylus and a recording stylus connected with said means and respectively movable at will into and out of operative position with respect to said record tablet, a reproducer stylus biasing weight movable relative to said vibratile means, means to support said weight in predetermined position in respect to said record tablet when said recording stylus is in operative position, said last named means comprising a member resiliently mounted on said weight and a contact element adapted to glide on the record tablet and carried by said member, and means to adjust the relative position of said member and said weight.

10. In a phonographic sound box adapted for coaction with a record tablet, vibratile means, a reproducer stylus and a recording stylus connected with said means and respectively movable at will into and out of operative position with respect to said record tablet, a reproducer stylus biasing weight movable relative to said vibratile means, means to support said weight in predetermined position in respect to said record tablet when said recording stylus is in operative position, said last named means comprising a member resiliently mounted on said weight and a contact element adapted to glide on the record tablet and carried by said member, and means to limit the extent of movement of said member relative to said weight.

CHARLES I-IUENLICI-I. 

